Compass-head.



PATENTED JAN. 21, 1 908. I

I No. 877,239. G. SGHOBNNER. COMPASS HEAD.

APPLIGATION FILED NOV. 28, 1906.

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GEORG SGHOENNER, OF NUREMBERG, GERMANY.

COMPASS-HEAD.

Specification of Letters Patent.

Patented Jan. 21, 1908.

Application filed November 28. 1906. Serial No. 345.541-

To all whom it may concern:

Be it known that I, GEORG SOHOENNER, manufacturer, subject of the GermanEmperor, residing at Nuremberg, Bavaria, Gerand enabling them to bear onone another.

many, have invented new and useful Improvements or Relating to Compass-Heads, of which the following is a specification.

In spring heads of known type for compasses the head joint is formed bymeans of two screws fixed in or of pins driven into each arm of the yokewhich screws or pins of course must be arranged in the axis of the headoint and consequently com el the tightening screw necessary for hol ingtogether the legs of the compass and regulating the friction between thejaws of the compass head, to be placed below the compass hinge. Ascompared with this, by the present invention a simplified constructionof the head of compasses with spring holding yokes is obtained, byperforated lens or semi-lens shaped disks, inserted in suitable recessesin the jaws of the compass head, being employed for mounting the latteron the compass legs, which disks when the holding yoke is sprung openmay be introduced or removed from between the legs of the compass andthe jaws of the compass head, and w Figure 1 is an elevation and partialsection;

Fig. 2, an elevation at right angles to Fig. 1;

and Fig. 3, a section of a detail.

In this form of construction the holding yoke c'de is given a springaction by recesses m being formed in the corners or rounded arts at theplace where the yoke arms c merge into the bar 6. The legs 9 h of thecompass have on their outer side, and the ich permits the arran ement ofthe regulating screw 1n arms 0 d of the yoke on their inner side,recesses which form a segment of a sphere with lens-shaped disks 7clying therein, which disks serve for holding the said parts apart,

The necessary tightening screw f for regulating the clamping pressure ofthe jaws of the compass head rests with its head Z against the outsideof one leg of the yoke, and by means of a thread n enga es in the otherleg, while its stem passes loose y through the suitably bored lensshaped pieces and also the legs g h of the compass head. In consequenceof this centrical arrangement of the ti htening screw f, the arm d ofthe yoke is relieved of any tendency to bend arising from the pull ofthe screw Oi course a modification might also be adopted, in which thejoint or hinge disks 1: have the form of a se ment of a sphere or halflens andrest with t ieir fiat sides in cylindrical recesses on the armsof the compass head, beyond which only'the spherical face inwardlyprojects.

I declare that what I claim is In a compass, a holding yoke havingrecesses thereln where the legs of the yoke join the head thereof so asto give said yoke a spring action, said legs having holes therein andrecesses surroundin the holes on the interior face of each leg, legs g,and h of the com ass having corresponding recesses therein, isks havingholes therein fitting in the orifices formed by the said recesses and ascrew holding the parts together.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORG SOHOENNER.

Witnesses LEONHARD KOERBER, HERMANN DOOHTEMANN.

